西南石油大学学报(自然科学版)

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Mechanism Study on Water Control and Enhanced Oil Recovery by CO2
Huff-puff for Shallow Heavy Oil Reservoir

Sun Lei, Pang Hui, Sun Yang, Hou Dali, Pan Yi   

  1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China
  • Online:2014-12-01 Published:2014-12-01

Abstract:

To solve the problems of rapidly increase water cut and low oil recovery in the later water-flooding of low heavy
oil and heavy oil reservoirs,we conducted laboratory physical simulation experiments and single well numerical simulation of
CO2 huff and puff in water control and oil enhancement. To find out the mechanism and feasibility,CO2 and reservoir oil/water
compatibility experiment and long core experiment of CO2 huff and puff are carried out respectively. The former has shown that
CO2 has capacity expansion and viscosity reduction effects on the heavy oil. At a certain temperature,as the pressure decreases,
the volume of reservoir water saturated with CO2 expands and the solubility of CO2 in reservoir water declines which indicates
that in CO2 huff and puff,water is trapped by the small core thus causing Jamine Effect,and preventing the water from being
produced. The long core experiment has also shown that CO2 huff and puff has a significant effect on controlling the water and
enhancing the oil recovery. This has also been demonstrated by single well numerical simulation of CO2 huff and puff.

Key words: shallow heavy oil reservoir, CO2 huff and puff, water control and oil increase, EOR, numerical simulation